Cumene production (benzene alkylation) — a PENG-ROBINSON process flowsheet
Benzene and propylene alkylate over a fixed-conversion reactor to cumene (isopropylbenzene, the feedstock for phenol/acetone via the Hock process); a downstream column recovers unreacted benzene overhead for recycle-quality purity while cumene leaves the bottoms. Luyben, Ind. Eng. Chem. Res. 2010, 49, 719.
351 views 0 forks
- Rigorous PENG-ROBINSON thermodynamics, solved by the same engine every simulation runs on.
- 3 unit operations modeled: MIX, RXN, COL.
- Focus areas: Alkylation, Reactor, Cumene.
- Thermodynamics
- PENG-ROBINSON
- Components
- benzene, propylene, cumene
- Unit operations
- MIXRXNCOL
Opens in a new tab, loaded straight into the app — no setup.
Read the step-by-step guideReproduce this exact result from Python — the real client.get_example() → run_and_wait() path, not a mockup.
from flowsim.sdk import FlowSimClient
client = FlowSimClient()
example = client.get_example("cumene-process")
sim = client.create_simulation(example["title"], example["flowsheet"])
result = client.run_and_wait(sim["id"])
print(result["status"]) # "converged"
streams = client.streams(sim["id"])Related models
Butene/isobutane alkylation
Sulfuric-acid alkylation of butene with excess isobutane produces high-octane alkylate gasoline blendstock; a conversion reactor stands in for the acid-catalyzed carbocation chemistry (a literal acid/hydrocarbon settler would need H₂SO₄ electrolyte thermodynamics this package doesn't carry — out of scope, same as the reactor already being a stand-in for the chemistry itself), and a deisobutanizer-style column recovers unreacted isobutane overhead. The high isobutane:olefin ratio real alkylation units run is maintained almost entirely by recycling that isobutane back to the reactor feed — closed here as a real Wegstein-converged tear loop, with only a small makeup feed replacing what the reaction actually consumes, rather than the previous version's isobutane leaving as an unrecycled product. Luyben, Principles and Case Studies of Simultaneous Design, Wiley (2011); Ind. Eng. Chem. Res. 2009, 48, 11081.
Hydrocracking reaction section
A refinery hydrocracker: heavy VGO (modeled as n-dodecane) plus excess H₂ is cracked over catalyst into lighter products via a discrete lumped first-order kinetic network, then flashed to knock out recycle H₂/light gas from the liquid product (Peng-Robinson). Conversion is set by reactor temperature and LHSV.
Benzene hydrogenation → cyclohexane
Benzene + 3 H₂ → cyclohexane in a conversion reactor, then a high-pressure flash recovers liquid cyclohexane and recycles the excess hydrogen (with a purge). The classic ChemSep recycle example — exercises reaction + recycle convergence.
2,6-Xylenol from phenol methylation
Liquid-phase methylation of phenol with methanol at 250°C/150 bar over a selective ortho-methylation catalyst, per US Patent 3,707,569. At 50% single-pass phenol conversion the reported selectivity is 70% to o-cresol and 25% to 2,6-xylenol (the further-methylated product) — modeled here as two sequential fixed-conversion reactors (phenol → o-cresol, then o-cresol → 2,6-xylenol) approximating that split, followed by a distillation separating the light methanol/water from the phenolics, with an o-cresol side draw. The column is solved with the side draw as a real MESH withdrawal (rigorous_draws) on Soave-Redlich-Kwong: every other combination plateaued — the default carve (side draw cut from a distillate/bottoms profile) on PR, SRK or a Ge-mixing-rule package sat at a 2e-3 temperature residual, the rigorous draw on PR at 7e-5; on SRK it closes to 1e-8 with the component balance at 1e-7. Read the phenolic split for what it is: 20 stages at R=2 between three ortho-substituted phenols nine kelvin apart is a screening cut, and a cubic with van der Waals mixing carries no hydrogen-bonding non-ideality for the methanol/water/phenol top section (PSRK now has the phenolic UNIFAC groups, but a genuine PSRK evaluation of this column takes minutes per solve).
Ethylbenzene synthesis
Benzene alkylation with ethylene (exothermic, 98% ethylene conversion) followed by a recovery column — 100% EB bottoms. From the ChemSep casebook (AIChE J 57, 655).
Ethylene oxide hydration to mono-ethylene glycol (MEG)
Ethylene oxide reacts uncatalyzed with excess water at 200 C to mono-ethylene glycol (MEG, antifreeze/PET feedstock); the excess-water dilution that suppresses the over-reaction to di-/tri-ethylene glycol byproducts is reflected in the large water excess on the feed, and a downstream column concentrates MEG in the bottoms while excess water leaves overhead for recycle. Kinetics basis: Ind. Eng. Chem. Res. 2009, 48, 10840.